Water treatment



Feb. 27, 1945. c. s.` KING 2,370,473

WATER TREATMENT 4 23 /Va P03 [7? vena? Feb. 27, 1.945.

cl2.y s. KlNG 2,370,473

WATER TREATMENT vFiled July 17, 1941 5 sheets-sheet 3 Weg 6 /VH// TAO/V.

[f 70 (No TKEAWENT) I I I I l I I I I I Mam@ PERcE/vr M30 EW/@Spi lazy l I IO I5 20 25 30 PatentedhFeb. 27,1945'` 2 'UNI-TED@)STATE 1 -fWATER TREATMENT nois D(Jrhaxfles S. King, Joliet, Ill., vassigner to Blockson yChemical Co., Joliet, Ill., a corporation of Illi' Application'July17,1941, seriaindioavza.

26j claims. f (c1. Y2101-23) j ions, ysuchas n The present invention relates to new chemical glass systems useful in the treatment of -water,

and to new chemical agents forV the ltreatment of'.

water and for other uses.

Inv particular, it relates lto improvements inA an art heretofore known, and tonew methods and agents for said art. The treatment of water refersbroadly to city supplies,boiler waters,v was tersfordomestic uses, asfor washing dishes and clothes, bathing and 'otherfpurposes and in gen@ eralitrelatesto the ,hardn`ess in such'waters.r

There isrexten'sive knowledge and practicein e the useof ralkali metal phosphates including poly- 5 phosphates to treat water.v j Referencel is made` to the following U. S. patents: I-Iall,v No. 1,956,515, reissued asRe. 19,719, Hall, No. 2,035,652, Rosenstein, No. 2,038,316; reissued twice as Re.A 20,360A

and Re. 20,754, and other U,j S. patents, such as No. 2,156,173 to Bird, yand'No.4 2,059,570 to Fiske,

Warrenand Bryan.

. As a result of prior developments it is*A known that the water-soluble vitreous glasses compris-y ing sodium oxide r(NazO) and phosphorus pentoxide (P205) havevaluableproperties in treatr ing water. `'Ihejp'resent inventionrelates tothat portion of ,the prior art field which involves polyphosphates, vand only the pertinent part of that,y

field will vbe discussed for vl,the purpose ofgexpllaningv the present invention. The termfpolyf, phosphate is commonlyiused-in the art ascomprehending metaphosphatesand othersalts of dehydrated ortho-phosphoric acid., Mellors Inij organic & Theoretical Chemistry, Ed..,1928, v ol.l 8, page 990, describes anddefinespolyphosphoric acids,v without,y however, making it clear .that

metaphosphoric acid-is one of, them. However,

industrial terminology includes metaphosphoric` acid as a polyphosphoric acid, land this industrial terminology is employed in describing the present invention. f

One of the functions ,of is to"sequester calcium and magnesium from the vitreous products silicates,` carbonates, phosphates andsulfate salts.v 'f 'f Inhibitionin -the priori artv is the action of a very -small quantity 'of vdissolved Na2O--P2O5'- Y `polyphosphateto prevent the precipitationk of solid products fromtheo'riginal calcium or 'mage nesium compounds inthe waters. 1

vlWhereas sequestration involves 'stoichiometri- `calamounts ofthe treating phosphate and ofthe ,hardness impurities in the' water, inhibition doesnot. Rather, it advantageously inhibits the precipitation of lmuch more material than 4is stoichiometrically equivalent to the quantity ofin-` hibiting agent used. I

` T he 'prior art vitreous phosphates for'such'purposes arernost commonly dissolved in water and the solution Yisthen employed,y orthe solid com'- pouncl is dissolved 'in all water to be treated. The agents have a high total solubility in water, and dissolve readily. Granularmasses of Lthe agent congeal on"bei`n'g wetted, dueto a highhy'g'rof .s'copick nature. The hy'groslcopic character limits the utility' of `such agentsgnotfin the lchemical functioning, but in the mechs'ainical' proceduresv of using the" agent. Also," theyare -quite runstable in Vsolution at higher temperatures,r` limiting their" efficiency in certainfuses, as well as` ltheir utility.'

-'lhe' present' invention` aims to provide new agents which *overcomer` one or vInore defectsv of these priorL art agents while having their valuable water-treatingproperties, and in some cases with improvements in such properties.

`It isan' object of the invention to produce new chemical compositions ofmore complex nature for use as a substitutev for' suchpriorart treat` ing agents, wherebyfnewproperties are exhibited, and whereby properties l characterizing v:the prior art compositions? are enhanced or diminished in f desired directions.

Another object ofthe invention is to produce new agents'ofthe typev referred to withconwaterscontaining them. Another functionk of y them is designated inhibition,

appears to render the calcium and magnesium content of the"v waters: inert to reactionfwith soap.

sequestrationl in the 'prior art is believed tobe' the result of a', reaction whereby thecalcium ormagnesium cations combine' with the dissolved NMO-#P205 polyphosphate to' incorporate the calcium or magnesiuml into' van anion radical, wherein itislinert to -reactwith soap, and other' agents whichnormallyreact with calcium cate' f 4a sequestration is theik action of an agent whichv trolled properties dependent-,upon composition.

, It is also an object of the'invention to produce chemical glass systems which are polyphosphate salts comprising'oxides Ofalkali metaland of metal from the group vconsisting of alkali-earth metals, magnesium, 'trivalent' iron," and alumi-l "num, regardless of the ypractical suitability for water-treating by methods practiced heretofore with 'alkali metal polyphosphates.

A particularobject is to produce complexes ci decreased hygroscopicity, increased stability, 'slower rate of solution, and non-congealing permanent granular form, without anysubstantial loss in value 'as Water-treating agent.

www

It is still another object `of the invention to produce a granular agent for treating water, such that the water to be treated may iiow through a bed ofthe agent to effect the desired treatment, without use of excess of the agent, and

without detrimental change in the porosity of the bed resulting from the action of the Water on the agent. Y

Still another :objectiof the invention is to produce a granular water-treating agent which may f be used as a component of a dry mix without detriment to the mix through undesired hygroscopicity of the agent. i

It is a general object of theinvention to produce polyphosphate water-treatingagents Wh'ich the `thermal treatment of the glass, for example, the rate `of cooling the melt. Thus, `there are known the following forms of NaPOa:

`(NaPOa) 1-sodium monometaphosphate (NaPOs) a-sodium trimetaphosphate (N aPOs) -sodiurn hexametaphosphate Theseare polymers. Quick cooling of ya melt providesithe hexametaphosphate.' 'Various mixtures ofpolyrners thusobtainas the cooling is varied. rllhe mono-form is insoluble in water. The triand hexaforms are soluble in water. Of the y solublgegmasses, only the hexaform is vitreous incorporate alkali metal oxide and another metal oxide of `kind and quantity selected for the particular properties which it mayiprodu'cesfl and accepted as having valuable properties for treating water `for sequestration and inhibition.

Within` the described system of sodium polyphosphates there "are known definite compounds.

i the more common. ones being shown in Table l.

It is a particular object of the inventionto pro.-

duce new polyphosphate water-treating agents having Aalkali metal oxide and oxide ofimetaflnfronr: the group consisting of magnesium;@thealkalielv y earth metals, `trivalentA.iron;:;,andialuminum;:said

selectedmetahbeingfherein referred: tofffori conveniencexas'iM: f

Various other :andanciljlary: objex'its:and,advanlL tages of the inventiorrrwill becomeaapparent from.

the following-description'andexplanationzof the inventiomzinr.: connection :withatheaccompanying Figi 1 'representsathe `effect-loi' fusion tempera-, ture fon the.;ca'lciumeseduesteringpower; otsodlu'm; vpolyplflosphateslu i Fig. 2 is a triangularV coordinategraph off-the-r new complexes of-thepresentdnventionzexpressed in 1 molargzpercents: ofy ifalkali: Ametall oxidepx-phos:l` phorusfpentoxideaandfathird. oxide of meta-laf.:` Y

Fig. 3 is .a fragn'ientary.l portion of` algraphy like, that. of; Fig. 2. where .the Valkali r metal ris.` sodium,.

and where the thirdzoxidewis-:of' magnesium Figs; 4,15; and 6 are graphs forf the fsodiurn magnesiumipolyphosphates;fshowingqrespectively the:` properties referredavtof-as. hygroscopicity,y se-l I questration;andinhibition, l

Flg.7 is aigraphcomparingqthe llygrose.opicitiesiL of" sodiumeM+polyphosphates -where .thefmetalt M f SODIUMPLYPHOSPHATES f The.artreferredgtmhas developedilargclymvith `the 5. sodium-W i polyphosphates.- f The; i fmetal-phose phateffcornpoundsf areznotfof fsimplecharacter .like i. f

manyother metal salts; and-theiactual character; of the substance.- is :note indicated .by.its simplesty empirical :forrnulaz:A In; orderfzto; predicate the in-` vention later to be described, atbr-iefereference to the. nature vofmetal;` phosphatesis in order-and is, given; Lbelow ineconnection withz-the s prior `artsodiumYpolyphosphates'.-`

'Theft sodimm` polyphosphates: yasxherein" referredtowint-.this` art; are vmolecularly dehydrated n phosphates-varying from thelratior. lNazO .to 115205` tof theerato. ZNazOltoa` V1PG).'., :.0r. irri-other. Words` varying withinicthe: system: sodium; metaphosf phatef Nal20sl-- to: sodium@` pyrophosphate (NarP'zOri.

Sodium polyphosphates zwithin this systemform. ,gl-assestzbyfmelting,i and coolingtg.. vThe .actualcharacterzofna glass-,zfor. exampleoflNaPOs, varies-by'.

polymerizationy,vso` that' distinctive@ formatore known; havingidistirrctive fproper.1',ies..-. Polymer.-v ization and depolymerization,aretcontrollable by@- Table 1 MolesofA Moles oiy i Y :Napo-3 Naz-O Formula Name.` l

v :s 1 Nannelsodiummpal@oxyph'osphm 4 i l NasPfgOli.: Sodium hexapolyphosphatc 2 l NaFlOla, Sodiuinftetrapolyphosphate l 1 Nalaow Sodium"tri-polyphosphateA These, polyphosphates likewise 'form' polymers.

As .the general rule in theart; only those'polymers" of V1colyphosphates. which result from quickly cooling the melted L materialhave't valueas water-v treatingl agents;` Theyjmust be vitreous; with the exception that crystalline sodium"tripolyphosL phate'may beused.(see USS. No..2,l174,614`).

Senior/L PoLyrHosPH/xrns AsiWArEae-TREATING v f A'GENrstf.

The` eiectivenessA lof l the `vitreous. sodium poly.- phosphates is determined also bythetemperature ofthe melt which is, quickly cooled; .The differ ent identifiable?. polypho'sphates do notV respond l identically'Y `to the variationsfin fusiontemperaf ture. I .have determined. the.v seguestering value of. several. polyphosphates made...at..varying ,fusion temperatures, Land then r`quickly. chilledytoa glass.,

The'` variation is Ashown in Fig- `l in which the temperature offthe fusion isplottedhoriz'ontally, and*` the sequesteringpropertyispltted vertically as parts" by weight. of. calcium chloride .(CaCl"2)` se.' questered `by 1 partby. weightof the polyphosphate indicated :'on the curves. The tests were made 'iwith' water havingjl gramI of CaCl per l5 0`cc." The phosphate complex was dissolved atl 4grarns' in 100 cc: The`water'1was titratediwith" the polyphosphate solution; At rst aA fprecipie tate occurs, which is then taken up byv added 'poly-` phosphate. When'the precipitate is dissolved, the

titration is complete. Fromthe'data the'amount' po1y' of calcium vsequestered by*v l gram of.' .the phosphate'is calculated.

In Fig. l curve vlllin'dicatlfesfthe sequestering power of sodium hexapolyph'osph'ate 1 It attains a `maximum with" increasingfifusi'oxntemperature;-v and increasing the vtemperature1dnes1no`t affect:

it.` Curved i' shows th'ef property for Vsodiumtripolyphosphate: vlt'has itsmaxirnum sequesteryThe sequestration different from the sequestration power for magnesium. I have found that for calcium sequesthat the value of polyphosphates in the system from NaPOs to Na4PzOv is about the same as for NaPOa.

OIBJEcrroNs ro SoDrUM PoLYPHosPHATEs The sodium polyphosphate glasses having power of sequestration and inhibition have objectionable qualities physically, and the uses of them to utilize their chemical properties are thereby limited. They are extremely water soluble, not in the sense that sugar and salt are soluble, for they do not dissolve that fast. They are however, so soluble that a mass of the product cannot be used to pass water over it for dissolving a minimum amountto effect the required water treatment. More than is needed is dissolved, becauseof the rate of solution of the glass. With a suitably lower rate of solution, new methods of treatments may be employed.

Another defect is the, gelling power glasses. ular or glassy form and become gelatinous, causing particles to stick together into a solid mass. Consequently it is not possible, on this account alone, to pass water through a bed of the material. The rapid rate of solution is also another handicap to such use.

The sodium polyphosphates in h ot waterrevert quite' rapidly to ineffective orthophosphates. On such account certain desirable uses of the agents are prevented, and in other uses employ the material ineiciently. Whena glassy sodium polyphosphate is powdered, as is desirable to make it a dry powder or a component of a dry mixture, for water-treatment, the powder is so hygroscopic that it causes the mass to congeal, if exposed to Water orto water-bearing or hydrated compounds vof a mixture, or to a humid atmosphere. As a result of these defects, the application of ,the sodium polyphosphates for treating water, is limited largely to dissolving the glasses and adding the solution to the water to be treated.

These defects are not only true of sodium polyphosphates, but of potassium polyphosphates and of the power for calcium may be` latter being relatively When wet with water they lose the gran- Yet for seother alkali metal polyphosphates. vBecause of these defects common to alkali-metal polyphosphates, and because of the less expensive sodium base, practically, the art has been developed and studied, to use the sodium polyphosphates.

` Attempts have been made heretofore to overcome some of these objectionable properties,.es pecially to overcome hygroscopicity. Coating the particles with a sodium -phosphate or intumesced borax have helped somewhat. (see U. S. No. 2,008,561 and No. 2,024,543), butthese only add surplus chemical to the treated water, beyond that required for sequestering or inhibition.

IMPROVE PoLYPHosPHA'rEs According tol the presentinvention the objec-v i physical and 'chemical properties, and. plotting `the water-soluble vitreous phase,

metal oxide remains 4as an importantand essential4 constituent, and in which varying quantities of vother oxides are present from the group of metals consisting of magnesium, calcium, strontium,barium, aluminum and iron.- By selection of thelcomposition, the hygroscopicity and the rate of solution may be` controlled, and the gelling. may be controlled or stopped. Thereby, new

methods of application of the polyphosphates have been opened up, and new 'mixtures are permitted.` For example, a granular bed of a chosen compositionmay be used to pass water through it, at a controlled rate, so that the water dissolves just-suicient of the agent to effect the desired treatment, andthe bed retains its granular form, requiring only renewal by adding more of the granular -compound to replace that dissolved.

According tov the present invention in the broadest aspects, new compounds may be prepared which have present invention.

For convenience in vsimply explaining thefpresent invention the compounds are represented as containing three basic ingredients, whereby' the scope of the invention may be graphically illustrated on triangular coordinate charts. The ingredients are: l

(2) Alkali metal oxide, suchv as NazO or K20- (3) Metal oxide, such as MgO, CaO, SrO, BaO,

- A1203 and F6203 It is not intended by this system of description and explanation to indicate that but one of the oxides of (2) or of (3) above must be used, and it will be shown'that more than one may be used.

However, in order `better to study and explain the effect of variables, it has been considered best to study the simple systems, as will be apparent hereinafter.

In carrying out the invention, any composition to provide the desired ratio of the oxides desired,

untilr molecular The temperature is such that a complete fusion occursand such that upon quickly cooling a clear vitreous glass results. lOverheating has no bad effects. Cooling small masses quickly is readily accomplished and assures clear glasses. By slowing the rate `of cooling, crystallization can occur. A' small amount of clarity, giving an opalescence or cloudy effect, caused by inclusion of water-insoluble crystals in .The crystal portion is not of value and hence such cloudiness is preferably avoided, o1' accepted when not so great as to impair the efficiency of the compound. y By making many compounds, testing their the vsuccessful compounds on triangular coordinate paper, I have found that a denite relation exists. Just as there is a. range of composition `objectionable features like the sodium polyphosphates, yet which have greater` and with the same chardehydration is complete. j

crystallization may destroy between 11.00% Nago` and 1.00% P205v including theintermediatamixtures, in which range the intermediate rangefromNaPOs to Na4P2O7 represente. the water-treating sodium polyphosphates, there isalso a like range for'otherrmetals. Thusv forthe bivalentmetals, Ca, Sr,.Ba and Mg,l represented; hereinafter by M, there is' a :range of- Mf-polyphosphatesk from MKPOS) to MzP2Of/.` For the trivalent metals Feand Al,y represented hereinafter byM", there is a range of M-poly phosphates M(PO3)3 to M"4(P2O7) s. I have found that when a triangular coordinate chart is madenat which one vertex represents 100 molar percentof alkali-metal oxide, alkali metal being hereinafter represented .by A,- and its oxide being A20; another Vertex; representing 100 molar percent of` P205, and the thirdr vertex .representing 100 -molarpercent of the metal oxide M"O or M2O3, Imay connect with straight lines 'thev corresponding terminals of the A-polyphosphate range and the respective M-polyphosphate rangesr as boundaries for vthe respectiveareas of the chartin which lie the compositions .of the invention. Thus, I havefoundthatthe compositionsI may be considered analytically as correspondingfto a` product' made from A-polypho-sphates and M- polyphosphates, without commission to the proposition that such definite compounds are present as such and independent of each other.

I haverfound that theM-polyphosphates do not possess water-treating qualities, and that new compositions only lose practical value as Water treating agents when the solubility becomes limited` for some practical usage. As the` complex approaches the line of M-polyphosphates inthe chartreferredto, the water-solubility decreases,

and other properties change, so that considering These .practical limits are variable according to the' specific character of the metal M. When M is trivalent, the molar percent of kM2O:x is preierrednot to exceed 5% inorder to providea practically valuable water-treating agent. Where the metal Mis magnesium, the molar .percent Vof MgOis preferred not to exceed reason. Where the metal M is alkali the molar. percent is preferred not to for the same reason.

When there isl but a slight` amount of meta-l (M) oxide in the mentv over a corresponding sodium polyphosphate for the same earth metal, exceed 17.5

is found, which is marked for Vsome qualities and slightfor others. In rone case, as is pointed out later. a complex having-as little `as 1 molar percent. of' A1203 in a sodiumaluminum#poli/phos-` phate, has a .hygrosccpicity one-fifth of that of the corresponding sodium polyphosphate'.

new compositions, an improvemolar: percent of using.: an oxide` of M;- the. improvements :overscdiumzpo-lyphosphates: for water-treatmentare of when theqmolar perand when the generally practical 4utility cent of MfzOs is as 10W as. 1%,

l\/I"O vis'as low as 2.5%. However, I-donot exclude Yfrom the scope of the invention. complexes -havin-gM-oxide belowl these preferred practical limits.

I have represented the extent of the improvementsfin Fig. 2, uepon a triangular coordinate graph. The vertex 2li represents alkali-metal oxidefin molar percent of 100. The vertex 2l represents P205 in molar percent of 100. The vertex 22 represents oxide of metal M" or M'" in molar percent o-f 100.

Point 23 represents the complex APOs such as NaPO'a;

Point 28 represents the complex A4P2Ov such as f",

NafiPeO'I. Point represents the complex M(PO3)2. Point 2t represents the complex' IVFePzOv;

. Point 'trelpresents the complex M"(PO3)3.

other cases the variations in asingle property i are Vnot so obvious ordetectable for'small usages offmetal M; Where an important property, orfa combination of several properties, is apparent at somelow content of metal M. that is taken as a lower v*limit for the preferredv .practical complexes.` I have determined that in the case of complexes of the Point 28represents the complex' M4(P2Ov)3.

Line RQi-fi represents lthe alkali-metal polyphoephates vof the prior art.

Lines 25-26 and 2'5-23 represent theV loca polyphosphates respec-v tions on the, chart for tively of M andy Lines connecting theterminals of the ranges ofthe M-p-olyphosphates to the-:range of alkalimetal polyphosphates are'drawn and are designatedly Emili and 32.'

Lines 29 and' Sil'form a zone on the chart in which lie thev complexes of the present invention involving M" metal, or Fe and Al. In this zone I havel found that 'line 33 generally defines the upper limit for the preferredpractical water` treating-complexes, at about 5, molar percent of Athe oxide of Iirc-n or` aluminum in the complex.

Dotted line 1Minv this zone defines the line oflower molar percent,` at about 1%, of oxide of iron or aluminums where enceare obviously apparent and sufficiently practical to warrant `using'compositions lying .on ,the

line Slifer water-treating. I do not intend to exclude from the'scolpe off theinvention complexes lying in the zone between lines 29 and 30 and between the Aline 34 and line 23-24, the preferred and practical Water-treating compositions lying in the said M"zone between4 linesA Lines 3l and 32 define a zone wherein'lie the present invention having bivalent metal M, of which the alkali earth metals Ca,',Sr, and Ba form one class and Mg forms another. In this zone I have generally denes the upper limit yfor the pre'- ferred practical water-treating complexes, of about 15% molar percent of MgO in the complex. The like limit for molar percent of oxide of Ca; Sr, or Ba inthe M"-zone between lines 3l and 32.

Dottedline 37 in this zone defines the line of lower molar percent, atabout 2.5%, of oxide of Mg, Ca, Sr, or Ba, where the benets of its presence are obviously apparent and suiiiciently practical to warrant using compositions lying on thefline 3l for water-treating.

the benefits of its pres'- i found that line 35 is about 17.5%, represented by line 36 40 online 3|.

ALxALr-METAL Heretofore the alkali-metal polyphosphates have been practically limited to sodium. Potas-` sium may be used, but its compounds are higher melting and therefore more costly to manufacture. In the present invention, where the term alkali-metal iskused, I contemplate both single and mixed alkali metal, such as the preferred sodium alone, or sodium and potassium mixed.

I' lpreferthe oxide of potassium not to exceedy 50 molar percent of the mixture of oxides of sodium and potassium, for one reason, to keep the fusion point lower' and thereby to reducecost.

`In addition to these reasons,f1 have found that in some cases,` the desired properties decrease when the molar ratio of KzO to Na20'l exceeds 20 vto 80.r

I'have made complexes wherein all the alkali metal oxide is X20, land whereinnvariousl ,ratios `ofpNazO to KzO have been employed, and'although they have substantially the Same chemical properties for treating water, kthe physical properties vary. In the particular rseries'tested, as .later illustrated, the improvement of Alower hygros'copicity of the complex begins to be lost `where the KzO begins to exceed the NazO.

Y FUsIoN In making the complexes various materials may be combined and heated to fusion, reaction becoming complete when any required dehydration is completed and a melt is obtainedwhich can be quickly chilled to a vitreous mass. Oxides and c'arbonates of the alkali metals and of the metal M may be used, and phosphoric acid,`phos phorus o-xides, alkali or other metalphosphates or polyphosphates, so long as the initial ingredients are sufcient in quantity to provide the desired residue. It is Ipreferred toheat above the melting point to insure a crystal-clear glass on chilling. l

EXAMPLE 1l A mixture consisting of l,23.0 grams C; P. 85%

I-lsPOi, 5.84 grams C. P "NaOH, and 1.62 grams 97%,Mg(0H)2 was heated with gradual rising temperature and was held fornone hour at 800-850 C. The clear liquid melt was cooled quickly with the resultant formation of a clear glassy material of the molar ratio: 13.5% Mg0, 36.5% NazO, and 50% P205. a mixed metal metaphosphate, analytically corresponding to 84.4 molar percent of NaPOa and 15.6 molar percent of Mg(Ps)2 or `by weight, 75.2% NaPOa and 24.8% Mg(vP03v)2. 0n the chart of Fig. 2, it falls at thevpoint designated EXAMPLE 2 A mixture consisting of 23.0 grams C. P. 85% H3P04, 7.60 grams C. YP. NaOH, and 0.78 gram` A1(OH)3 was heated as in Example 1 and held for one hour at 900 C. The clear liquid melt This compound is In the following" discussions of properties of the complexes as varying within numerous series,

`the analytical composition by weight or by molar percent is omitted, as well as location of the compounds on the chart of Fig. 2.

SoLUBILI'rY Under the head of solubility are included rate of solution in water, and amount soluble in water."v 'A' highL solubility is desirable for producing concentrated solutions for use. A low rate of solubility is desirable for reasons set forth above.

-ute for,4 hours.

was cooled quickly with the resultantformation ,l

of a clear glassy material of the molar ratio: 2.5% A1203, 47.5% NazO, and 50% P205. This is a mixed metal polyphosphatej analyticallyv corre- 'sponding to a product made from 2.45 parts A1203, 29.0 parts NazOV and 68.5' parts .P205 by weight. 0n the chart of Fig. 2, it falls at the point 4I, the junction of line 31 and liner3l.

f physical property values decrease. The preferred Fromy the above examples, itis seen that point 40 falls on the boundary line 3|` of the zone for its complex, and that although point 4| lies alsov f on line 3|, it falls within the corresponding boundary line 29 for the zone of its complex.

' Sodium polyphosphates of the prior art have a very high rate of .solution and high total solubility; In addition they tend to congeal into gummy resin-like masses when wetted. According to` the present invention complexes may be Lmade which rhave a low rate of solution, a high solubility, and no tendency to congeal.

toa yseries of `complexesiprepared in 10 to 20 lmesh granulation. In a vertical tube to form a Vbed #1% inch in diameter and 1.25 inches high, :containing 15 grams of a complex, cold water Waspassed at the average rate of 1000e. per min- The amount of complex dis# solved was; determined by analysis of the dischargel for P205, expressed as parts per million (P. P.` M.)" P205 dissolved by the water. The compositions oi.v the series were according to Table 2, which also gives the P. P. M. P205.

Table 2Rate of solution v Molar ratio P; P M. Item P205 dis- Mgo Nalo Pio. Swed i1 e. 5 43. 5 5o. o 90.0 2 13. 5 3s.l 5 5o. ok 2. 5 3 7. 0 46. 5 46. 5 125. 0 4 15.4 42. 3 42.3.A 2. 5

Table 2 shows that the higher content of MgO greatly lowers the rate of solution. Items 2 and 4 with a low rate of solution retain their granular form without congealing or swelling, and become dry when exposed to air. making a 25% solution. .The rate of solution varies with-the-composition of the complex. By

changing theMgO to FezOa or BaO, yabout onethird and live-fourths respectively of the molar amount for MgO is required for the same effectiveness in securing low rate of solution.

- The items 2 and 4 having low rate ofk solution f are within the practical range of effectiveness for inhibition action, and because they do not congeal, they may be used as filter beds for iiowing' water over the material'in treating the water.

1 Other new uses are permitted which likewise have kbeen impossible heretofore, when only the sodium polyphosphates have been available.

It may be stated also that as the alkali-metal content of the complex increases, the desirable To illustrate these properties reference is made v All the items permitV line 36 forthe alkalieaithfneta1's,-all 'the complexes are soluble 'tofform 25% 'solutions `'in Water.

In Fig. 2, the point 43 -representsthe'compo- 55,

sition With molar percentages of This compound is practically insoluble in Water,

and in dilute and concentrated hydrochloric acid ornitricacid. As the composition maybe varied on theline of constancyv for MgO to increase. the

Q Na2O content` at the vexpense of P205, .the solubility becomes perceptible. `Also as the composition may be varied-from point43won line .3 l, the rsolubility vbecomes preceptiblauntil at ,the junctionI Iof lines 3l and itisextremelyuseful and. in thepre- `ferred practical field. 'Thechangeufrclm s'olu-ZU bility toinsolubilityis gradual anddoesnot permitoidening-a limit' except inv terms of some Water` treatment.

aref-useful'forwater treatment, ars/those vitreous mixed-metal polyphosp'hates;"which are AWatersoluble. i

HYGROSCOPICITY The sodium polypl'iosphates have undesirable `glasses consisting analytically oi the defined 30 'nyerescopicitysuen that :compounding of them into dry powclerymasses is impossible. Thus, a mixture Aof equal Wparts .ofsodiummmetasilicate i. ,Qrystallinetrsod-ium phosphate, and dry sodium -polyphosphatefexpcsed for 24 hours at '75% relative humidity at room temperature, becomes moist 40 and sticky, and will cakeon drying out. However,l in, a. like` composition .having .equalparits by .fyveightot .a Crystalline sedium-metasmcate Crystalline .trisocliumphcsphate f,-Polyphospliate.` complex NazO 43.5 moles P205 50.0 vmoles "the mixture 'isistable and unaffected bysuclicon- I ditions, and has jthesaine Lchemicalpropermesas the'cakingmixture, Vforex-amplewhen used-asa Water-softening -dish-washirigecompound;

I"ll'ie" improvement in decreased hygroscopicity is further evidenced byY a series of complexes: ex- "posed to air .for 2 hours `at 85F.'ofI65'%-.re`lative Y1-humidity ina-humidity-control cabinet. 'lThe 1resultsi are shown in Table 3.

from thehardness constituents of -Waterscon- Table 3-"Hyg1'oscopicity -Molar ratio of fcomplexg affermava limits offlines`33 for-Mm,"A line-'35 -for fMg'Qand In general it isshovvnl thatas the total molar ,metal oxide content increases, the hygroscopicity increases. .Items landnlare-,sodiiun polyphos- Y.phatesof theprior art, and :show .by .contrast the improvement in decreasedhygroscopicity .caused `by .thepresence of ,oxide o-frmetalM. The oliemioal 'water-treating propertiesl remain substantially the vsaine .as the sodium polyphosphates, so

that by varying .the kind .and amount of .oxide of metal M, it is possible .toy control hygroscopicity.

f .ISTABILITY The polyphosphates .of' the prior art .andof' the vpresent invention revert'in water toorthophosphates, which lack thel valuable Water-treating properties. The rate. of reversion in cold Water is slow, permitting practical use of cold Water solutions. In hot Water, the prior art sodiumjpo'ly- 'phosphates revert'rapidly makingthem less eincient for luse tolpreventqscale'inyboilers and'heatexchangers. At '100` Cf, the rate of reversionis so (fast,` that `they Vare generally consideredl unstable.

The complexes ofthe present `inventionare -much more stable Ain hot Watersolutions. 'They A retain their unique properties for a longer `period iii-hot Water thantheprior art sodium polyphosphates. This is `evidenced Vby comparison of' a prior art sodium polyphosphate and of a complex of the present invention as shown, below in Table 4. In the test a 2% solution of each complex iniwaterwas boiled in a reux'apparatus toi-preventconcentration,r and the orthophosphate con- "tent determined at intervals as ameasure of the percent' `of the original complex which reverts` to Vorthophosplriate.

` ..Tab'zed-Smbiziry used Percent reversion 'in Mgo Nago P205 l hour 2 hours 5 hours 7 hours 50. 0 50. 0 18 32 59 67 V6. 5 43. 5 50. onf 13 I 22 38 f 42 i From a vplot of .theseclata it :may'befseien that at about 7 and4 hou-rsthe new complex-has the status of the oldat about 3and.2;hours.1esl ectively; .and alsoI thatl the -rate .-ofnreversion ismuclrlower. Thus, 'the Unewv complexes are `:more:'eieientv for hot waters, and also permitof uses heretofore not lpracticable. i

:INHIBTIGN I The use of polyphosphates'to prevent precipitation of` calcium and 'magnesium compounds taining such hardening ions, is practically `limited to the use of only `a few-"parts of the polyphos- Molar ratio -Per cent Item gainin Mge cao sro Bao 1120i FezOs NazO P205 H20 50. 0 V50'. 0 7. 4 42.9 1.53.16 0,305 y 47.5 50.0 1.3 40.0 "50.0A 0:56 33. 5 50. 0 ,0.13 .40.0 50.0 0.36 33.5 50. 0 0.13

43:5 50. 0 1.'.75 36,57 50.0 n.35 45.5 50. 0 2;(35 40. 0 i' 50. 0 0135 36. 5 A50. 0 0.20 62. 5 37. 5 1 1'. 0 '50. 6 113811 15.".5

'pound'. In other cases, the complex may be sephates per million parts of water. The complexes of the! present invention have this vpowerof inhibition to high degree, and this power is also present in complexes falling Within the polyphosphate zones Ml and M'" of Ilig.2, beyond the'limiting lines 33, 35 and 3 6 already described. For inhibition usessuoh complexes beyond theselines are pared" to a prior art sodium polyphosphafe, is

considered to fall within the broad scope ofthe 'present invention, but the preferred complexes 'lie lin the areas expressedv as preferred; because lected for some'desirable physical property.

kThefeiectiveness of the new complexes, comevidenced inl Table 6. A liter of water containing 13.5 grams of hardness 'as' CaCOs, was treated with varying amounts of numerous new complexes until lthewater was fully softenedl against soap. The amount of 'the complex so required is given in the table,

Table E-.Sequestration of their valuable combinations of properties, such as low hygroscopicity, low but useful rate of solution and stability, whereby they are more universally useful. f Thel value of the complexes for inhibition is evidenced by the -results given in Table 5. :Water containingvcalcium bicarbonatel as the hardness agent, in amountv equivalent to a hardness of 10001?. P. M. of CaCOawas treated with 2 P'. P. M.

ofthe complexes shownin the table, and held for ,one" hour. at 80 C., which conditions normally y induce precipitation of CaCOsL "The amount of precipitation was determined and is' given in Table 5 as percent of total hardness precipitated.

' Table s- Inhibition yphates. Asodium-polyphosphate changes little Vin its .high y ,sequestering power Afrom about 0% to 10% molar Molar ratio of complexr Pe'rcent Item rprecipita- Mg() A1203` N520 P205 non i 0 0 y45 to 5o Item 5 shows that no treatment causes about vhalfthe calciumto precipitate, and item l shows that therprior art sodium polyphosphate reduces this to 21.5%. The new complexes ofitems 2, 3 and 4 reduce ythisstill further, and therefore evidence greaterpower for inhibition under `these conditions. f

' That union of calciumor magnesiumions of hard water with a polyphosphate, which prevents reaction of the iorrwithv soap, that isthe action vof sequestration, is asjcharacteristic yof the new complexes as of the prior art sodium polyphosvIt is shown lbelow that'a magnesiumratio of MgO, starting `.from the sodium metaphosphate variety. But as shown above the hygroscopicity decreases asthe MgO .content 1n- ,creases such that at l'molarpercent-of MgO, Ikit is -usefulin a` dry vpowdery'-'dish-washing com t 1n yended Item 1 represents prior art, and it is seen from items 2 and Sthat the sequestering property is not altered by the MgO content.. All the complexes are of thesame orderof utility for sequestering. Thus a complex may be selected having the most favorable physical properties for the use SEQUEs'rRArIoN IN DIsHWasHIre COMPOUNDS I A InV practical application 'of the invention to j utilize the power of sequestration, the invention forms on glass, from'the insoluble metal soaps in a cleaning process. y of nlm-formation is the, objective.v

yhas been developed further into a dish-washing compound, using a magnesium-alkali-metal polyphosphate, exemplified as followsz.

A test has been developed to measure the effectiveness of the polyphosphates in general. This test is based upon the prevention of film-formationon glass or dish surfaces. A film readily formed from'using soap in waters having hardness, or formed from soap produced in water by the action of alkali on saponiable fats involved Reduction in or prevention The testy conditions are kas follows:

Five clear glass plates5 inches square are soiled on one side with 2 to 3 grams per plate of a standard soiling' agent, which is:

- Y Y Parts by weight Peanut butter f. 2 Butter 1 Lard The agent is spread on with a spatula or the like.' The platesare then washed in a domestic Vtype dish-washer of 1-gallon size, using water of x20 grains of hardness per gallon, at130 to 140 F. for 5 minutes, using,0.5 oz. of compound vper j gallon.y Theyfare rinsed thoroughly with the same Water at 135 'to 140 F., and air dried.

The process is repeated 15 times, using on the '70 odd-numbered cycles the first face of the plate,

andon'* the even-numbered cycles, the second face of the'plate. Then theve plates are stacked into apile and placed on aA black back-ground. The accumulated filmA shows up visually, and a record for comparison may' be I nade by photothe complex polyphosphate.

. propressively .changedf .'Ihe measured .eiect the gain fin percent ,.at190" Feat-65 fjzzrel e ,humidit s material of substantially; the sa-Ine` rl'ineness conditionamavabeireadilm preparedsuth: met n0 film is `apparent i .ai pile, againstgtliexbilaclipackphate and to sodium tetraphosphate, :the visible lffrlms are Imoderate and intense respectively, 'and mthereforefnot perfect for .the prescribed test.

, It will be lappreciated thatasticeMSOcontentA ofthe complex rises, the solubilitydecreases (see lvFig. 8), thus mitigating'against the-advantage, fcompared `to thefmore soluble similarcomplex For the ff complex a sodium-magnesium .polyphosphate complex,- it has ibeen determined-'that-for dish-wasl'iing the practical superiority over -hsodium'metaphosphateiliesin atherranee of-,zfpoly- .phosphates iliavingvfrom :215' tcl8 molar .1p eroentiof l *Mgop mot .imorefftharrr molarxpercentso; E295, and :not: moregthanzxzzmoilari percentiwof alkalifmetal oxide, when-.testednas above innaacompolmd -as above iwith'equal;partspgorvstellme triSO diurn @Land phosphate, crystalline sodium metasilicat.

than sodium may be `used i-nall the ingredientsof .the dishwashinfg f compound, l,sodium being .the most common, least,,.expensive,....and lhence ypreferred forni. v

.,-All ali=Metal-.OX1de The effect oftchangingiall,iornpart ofwtheazO of 'the new rcomplexes,ptonsKzQois.: illustrated in Table i7., Adeniteiformulatien bas been'ohosen i in 'which' .the molecular.=.rat.ios;lotMgO, P205. .and

`alkali metal .areexed-:aandiithe aikeali metales ,Omietll t y litignosoopicitv.. tengas weight of in 12 hours The Liivexitems :abovevfposses'sssubstantially1 the ,1 saine value 'iforlinkhilition and sequestration, and

=unti1 ;K2O,;begins' ,-toepredorninate fthe-l alkali-metal .oxidecomponentgthe hygroscopieity:.remainsalow The preferred; ioomponndsitherefore 'have .at least 50% of the;allalimetalias'NaO.

i SELECTIONorCoMPrExEs The speeic. properties ..yary..,accdrd\ing. to f the composition `oi" .the.c.omp1ex, andlthesefects of changes are .more `partieularly reflected .sin the physical properties` .than in..the., eliernical,water .treating properties. .-.Thusfwith ,suncient--or ...fu-11;:

Alkali-metals other y; utilise-remuer lz5 l eenzame graphy.` :Aznompoundgiperfect 'ioil'thegaboyeitest zlcnowledgeeof anypetven asystem.-itispossibleto selecta*composition having :anoptimum :pomfbinatiorn off propertiesf'rnefm neriniwliiehfthis :m appa; ntfromtheioldetailed; explanation .of variations. in.; properties-.for one system. i

THE PomfrHosPHATE SfYs/rEMf-'MoO-'NezG-QMOs vNurrlerous .complexes athis system 4have 4been Selected VAto A,demonstrate theizariations. Yin properties.y In Fig. 3, aiportion of Fig. 2 has been reproduced with the same indicia.. The lines 23-24, 3l and 3.2 outline thepmoreuseful end of the zone for the system. Line 23-24 is the line of prior .altpolyphospliates. Line 50 represents series A of ,complexes the properties of which are illustrated in vother figures., Table 8 gives the formula 7for series A, and for other series B, C and D,

identifyingithe seriesA and formula with lines 50,

q l In graph-form figures about to beidescribed,

kthe .compleXesqareidentified.by L.the "iseresfin- .,iicia, fromzwhioh tllezcomnesitionfmay:.berdetermined :by referencetthe erenbzandto' Krabi@ s. F1o: 4', HYGRoseoP'IcITY j v 'L Series; A;"B,Q .andLDg-Jand.. prorartcomplexes, have been testedto olelierlrlineV the gainin weight by adding Waterjin, zihoursiat -859i. at.65.% relative humidity.' ,'.lThe-.percenteainin.weight is yplotted'vertieally'in115g. lHolZontally, the molar percents ofMgO for the series A', B, 'C and D are plotted,.givingztheicurves respectively 55, ...56,51and58 forthe saidrseries. Point 59, common tothe curves representsthe hygroscopcity of theoolflplexy of pointl23 in Figs. 2 and 3, of sodium hexametaphosphate. ,Po'int 60 represents another sodium polyphosphate of-leompositionat point 6| on Fig. l3. i

Line 555-60 vin Fig.A 4 represents theghygrm scopicityofcomplexes on the line 23f6| in Fig.,3. Lines 55, 56, 5'! and 58 represent the hygroscopicities of complexes respectively on lines 50, 5|, 52 r. and I iin Fig; `3. AThe. composition lines `in Fig. 3: `Zivil-24., 50,5 v5 l 52. .andi 3 11,.. andnthe,hygroscopicity lines:5924511555,1156;5l and@ 5min'.Prisml4, follow :,a `;c,orrespending,f.generally,y fan-shaped pattern, --.S..h0vv.ing ardenteziorder,inlnhenges .of hyg'ro- V.SCODCY vllvill-.langesf ilflioomposition. 'The .fact that line of series A shows hygroseopieity-n creasing with increasingcontent of MgO, does not indicate that this. seriesV is disadvantageous, for thevreferencebase for :measured improvement in Fig. 4 isnot #thefpoim--ea but father, itis-'the line 5 9'-6 0, inacoordancewi-th the; said-pattern. :lzseovesrmrrow 'f.;.In--Fig;: 5.:hasi'been=.plotted yerticallyf-the `grams off complex required` to. softenegainst soap, l -liter t-of materna-ying .13.5 .grains of hardnessasrCaCOs. -I-.Iorzon'tally,V has; been .plotted the .molarpercent --OfMgO-fi-Ir thefcomplezgesiof series A,fB C and'D. 1.2911111153-arepresentsitiie; sequestering powerorsodmm 'hexametenhosphate of pointfzaffimnief. '.Linesfdiie-66iandf'ilnrepresent tneemount nf complexes of the indicated series required to soften the water. j

The curves follow a system in definite order with the fan-shaped'pattern in Fig. 3 of lines 50, 52 and 3|. It is shown that within certain limits, for example up to molar percent of MgO on line 3| in Fig. 3, or'up to point 68 on said line,

the new complex -is fully as efficient as sodium hexametaphosphate, an important difference being (see Fig. 4) that the new complex (point is practically non-hygroscopic.

FIG. 6, INHIBITION lIn Fig. 6 is plotted vertically the amount .of CaCOa precipitated from. a water hardenedwith calcium bicarbonate, of 1000 P. P. M..CaCOa, by

heating for 1 hour at 80 C. in the presence of 2 P. P. M. of a complex. Horizontally, is plotted thev molar percent of MgO in the complex. .The line marked 'l0 is the amount, as a range, which is precipitated when no complex is added. Consequently, the lower the curves in the plot, the more eiiicient is the complex for inhibition under the described conditions. Curves 12, 13 and 14 respectively represent the results for series A, B,

C and D.

' Series D falls .on line 3| in Fig. 3, and it shows The glasses of the present invention o iier such obstacles. As stated above there is a reversion reaction whichis slow at low temperatures and more rapid'at elevatedy temperatures. It has been shown that the glasses exhibit varying rates of solution.v It is readily to be understood that conditions may exist such that the rate of reversion may exceed the rate ofsolution, or so nearly approach it, ythat it could be difficult to secure eiiicient solutions for water treatment with slowly soluble glasses. However, such glasses and their solutions have effective fertilizer value.

The characteristics .of the glasses to dissolve Lare illustrated by reference to the. system of series D, whereinthe molar vpercent of P205 is v50, and thecmtents of NazO and MgO are varied.

Using a temperature inv the range from to .30UMC., the effects of composition, fineness of' division, amount of solid in-contactwithwater,

andtime of contact with water, have been' studied f as factors involved in dissolution of the glasses in water.y

Fig.` 8 shows a curve 85 representing the concentration of solution produced, using powdered material passing a 60-mesh screen, in the quan- -tity of 100 grams of solid per 100 grams of water under standardized conditions for 10 hours. The

that the inhibiting powergradually improves as the MgO content increases, being constant from about 14 to at least 30 molar percent. For series A, the inhibiting power has ymaximums .greater than for series D. The pattern of the curves up -glasscomposition was varied so as to show the effect of increasing content of MgO upon the conto about 5 molar percent of MgO follows a definite order of. Fig. 3. than sodium hexametaphosphate, found at 15 in Fig. 6 and point`23 in Fig. 3.

COMPARISON 0F SYSTEMS VARYING'M point In Fig. '7, a comparison of systems has been made as to hygroscopicity, on complexes of nearly 'the same order, varying in the metal M. The

complexes compared are the sodium-M-polyphosphates. Where M is divalent, the metaphosphates on line 3| of Fig. 2 are used. Where Mis Fe the metaphosphate on line 29 of Fig. 2 is used. Where M is Al the polyphosphates on line 3| of Fig. 2 are used.

t In Fig. 7 the hygroscopicity is plotted vertically in the same terms as forFig. 4. Horizontally, is plotted the molar percent of metal M. It has been found. that the values for M" as Mg, and for M" as Ca, Sr, or Ba arev substantially the same, and

one curve 80 has been drawn to represent the hygroscopicity of such sodium-Mfmetaphosphates. Curve 8| represents the hygroscopicity of .sodium-aluminum polyphosphates, falling on line 3| in Fig. 2. Point 82 represents the hygroscovpicity of a sodium-iron-metaphosphate, falling on line 29 in Fig. 2.

f These show that. the trivalent metal M is 4more eiiective to lower hygroscopicity than divalent metal M, and that for this function the divalent metals Mg, Ca, Sr, and Ba are substantially equivalent.

a SOLUBILITY As stated above the `term solubility comprehends rate of solution and amount of material capable of being dissolved in a given amount of water at a given temperature. A precise value for the latter property is a characteristic of many chemical salts. However, there are other factors which sometimes make it diflicult to determine total solubility or to determine if there is a total solubility. y f .l l

a fan-like pattern like the series lines in All the compositions a.shownare better centration of solution thus obtained. At about 15 molar percent of MgO, it is seen that the solubility, asv plotted in terms of grams of dis-l solved yglass in-100 grams of` solution, begins to drop., Thus, for making solutions to be added to water,'thelmore`soluble forms up to abouty Quantity Exposed to grams Water Expressed Solubility 1.0 gram 0.11 10.0 grams 0.70 100.0 grams 3.39

From' the foregoing it is to be noted that in the largest use, the water had capacity for at least 3.39 grams in solution, yet in the smallest use the 1 gram employed dissolved only tothe extent of 11%, far below the said capacity ofthe water. A slow rate of solution is evident.

l lThe time of contact was extended using the same glass of 30 molar percent MgO passing a 20G-mesh screen. The results were as follows:

I-Iours Exposed Expressed Solubility All v.of these results show the desirability of iiowing water through a bed or over a bedof the divided' glass, controlling rate, composition, and lcontact, in order to secure the desired addition of the treating agent to the water involved. Some compositions may be dissolved in a few minutes, others not. A complex of 20 molar per-v centMgC) at 60-mesh granulation with an equalA weight 'of 'water win forml a 25%- soiunon in 1.o hours, but it is practically impossible vto obtain complete solution of l'gram of a complex Yof 15 molar percent MgO in 100 grams'of water in 10 hours at 25 C. The circumstances of use will determinel what type of composition is to be selected vfor its solubility characteristics in such use. The complexes of the' present invention appear to have an almost innite solubility 4with -a rate of solution decreasing as rthe elective metal M is increased.

The use 'ofsuch slowly soluble 'complexes in other `fields, such as for fertilizers, takes advantage of the slowness of dissolution. Such useful compositions, rvas well as many of the rapidly solublel ones, are characterized by no hygro- `scopicity. ".lhis is another valuable property for fertilizer use. The glasses may-be used'primarily to dispense `P205 to soil. Also, they may have X in whole or in part as the alkali metal oxide, with -or without calcium las the metal M. Thus, it is possible to make a glass complex within the present invention Awhich provides phosphate with potash, or with lime, or with both, which is non- 'hygroscopid and of vcontrolled `and slow availability. y I 1 The-detailed description lof -certain compounds, and certain uses thereof, are not to be considered as limiting the invention -comprehended `within the scope oftheappend'ed claims.

The present application 1is a continuation in part of -my `prior "application ESerial No: 360,065, 'iiled October?, 1940, Lwhich prior application is Idirected to ajchemical-composition'and process foi making-the same,` the 'present application being directed -to methods of ytreating water.'

-I-claim:

1. The method of treating domestic vwashingl waters Qfor bathing, laundering, Adish-washing `and Athe like which comprises adding to the water ya small amount of the substance of 'a water-soluble glass, said substance consisting yof a complex'which is a homogeneous fusion product--consisting analytically of the normal oxides o`f-sodium, magnesium and phosphorus in which the molar percent of MgO Varies from 2.5'-to 8, and in which the molar" percents o`f`P205 and of NazO are ieach not over 50.

2. The method of treating dish-washing water which*` comprises adding thereto a small ,amount of a compound having 'equal parts byweight of crystalline tri-sodium phosphate,N crystalline sodium metasilicate, and a complexwhich is a homogeneous "fusion product consisting analytically 'of the normal oxides Iof sodium, vmagnesium and phosphorus in `which the molar percent of M'gO varies Ifrom to 8, and in which *the molar perrcents A4of P205 and of Na20 yare `each not over 50.

3. The method of treating domestic Iwashing waters for bathing, laundering, dish-washing yand 'the like which `comprises adding to the 'water a small amount "of the substance of a water-.soluble glass, said substance vconsisting of `-amcomplex` which isa .homogeneous fusion product consisting analytically'of the normal oxideso alkali metal, magnesium and phosphorus in which the molar percent of MgO varies from 2.5 to 8, and in `which the Jmolar percents of alkali-metal oxide, :and 'of P2051are-eachnotover 50.

f4. The method of ytreating dishhwashing water which comprises adding lthereto a* sm'allamount of a compound having equal lpar-ts by Weight :of solid tri-alkalimetal phosphate, .solid alkalirnetal .metasilicata and complex-'which lis a lh'omogeneou's fusion product consistinganalytically L75 precipitation of compounds having the hardeningl 'of the normal oxides of alkali metal, magnesium and phosphorus in which the Vmolar percent 'of MgO varies from 2:5 to '8, andv in which the molar percents of alkali-metaloxideand 4P205 are each not over 50.l

l5. The method of treating water "having hardness which comprises adding to the Water the substance of awater-soluble water-'treating glass, said glass consisting of a homogeneous fusion product analytically consisting'of A20, P205 and M0 wherein A is alkali metal 'and M 'is `divalent metal selected from the groupconsisting of magnesium, calcium, strontium and barium, the P205 being 'present in 'the range from A331/3 to l50 molar per cent of the total molar contentof -sad oxides, and the MO being present to an extent in the range 'from 2.5 to30 molar per cent of said total molar content of said oxides, vand the A20 being 'present in an amount ranging upwardly from a `minimum of 2O molar vper cent cfsaid total molar content.l y

6. The method ol treating water having hardness which-'comprises'flowing the water past and in contact with a substantially nonehygroscopic water-soluble vitreous glass consisting of a homogeneous fusion product analytically consisting of A20, P205 land M0 wherein A is `alkali metal 'and Mis divalent metal selected from the group consisting of magnesium, calcium, strontium and barium, the P205 beingpresent inthe `range "from BB1/gto 50 molar percent of thev total molarvcon tent of said oxides, and the'MO being present'to anfextent in the range from 2.5 'to 3D molarper cent of Isaid total mola-r content 'of said oxides, and the A20 Abeing present in an amount ranging upwardly yimma-minimum of 20 molar per cent of said total molar content. 1 I

7. The method of preventing incrustation in systems containing water capable of depositing "scale-forming substances which comprises adding to the water therein the substance of a watersoluble water-treating glass, said glass consisting' of a homogeneous fusion product analytically yconsisting of A20, P205 and M0 wherein A is alkali metal and M is divalent metal selected from the fgroup consisting oi magnesium, calcium, ystrontium and barium, lthe- P205 being present in the range from 331A; to molar per cent of the total molar ycontent foi said oxides, `and the M0 being present to an extent in the range from 2.5 to '30 molar per ycent o'fsaidtotal molar content of lsaid oxides, and the-A20 being present in an amount ranging upwardly from a minimum `@i molar percent of said total molar content.

8. A vprocess of softening water which comprises subjecting a `c lua-n'tity of water `to contact with a water-soluble glass consisting of `2i homogeneous fusion product ana`.'lytica`lly 'consisting yof A20, PzOs-and M0 wherein Als alkali metal and M is divalent metal selected from Ithe group consisting of magnesium, calcium, strontium and barium, the P205 'being present in the range from l33% to 50 molar per cient of the total molar con- -tent of said oxides, and the-lVI'O being present 'to an extent in the rangeirom 2.5 to 30 molar per cent of said total molar "content of said oxides, .while dissolving some of ythe substance of `said 'glass .-i-n the isaid' Iwater and `while providing `a 'water-treating solution thereof, `and mixing said solution with water to rbe softened, landtire 4im@ being present in an amount" ranging upwardly from va rminimum of 20 :mo-lar ,per cent fofrsaid total molar-content.'

r9. A ,process for inhibiting in hard waters the i in the range from 33 i/ elements' of the'v water,"which comprisesadding to thegwater the*r substance of Aa water-soluble water-treating g1`ass',ff saidglass consisting of a homogeneousfusion product analytically consisting of A20, P205 and MOvvherein A is alkali metal and Mis' divalent metal-'selectedirom the group consisting of magnesium, calcium, strontium and barium-the P205-,being present in the Vrange from 331/3'to 50 molar per cent of the total molar content'offsaid oxides, and the M0 being present lto van extent in the range from 2.5`to30 molar per cent of said total molar' content of said oxides,

and the A20 being present in an amount ranging upwardlyfrom a minimumA of 20 molarper cent [of said total molar content.

10. The method of treating boiler Water to inhibit the formationof scale whichV comprises adding-to the water the substance of'a water-soluble-water-treating glass, said glass consisting of a homogeneous `fusion Aproduct analytically consisting of A20, P205 andfMOWherein iA isalkali metal and M is divalent metal? selected .from'the `calcium, strontium and barium, the P205 being present in therange from 331/3 to 50 molar per 'cent ofthe total molar content of said oxides, and the M being present -to an'extent in the range n from 2.5 to 17.5 molar per cent of the total molar group consisting of magnesium, calcium, strontiumgand barium, the P205 being present in the range from 331/3 to 50 molar per centof thev total molar f. content of said oxides,.and theMO being present to an extent inthe range from 2.5 to molarper cent of said total molar content of .said "oxides, and the A20 being :present in an amount ranging upwardly fromia minimum of 20y molar'per cent of said, total molar' content,

:"11.r The method .of treating domestic Washing waters for-bathing, laundering, dis,h-vvashingl and the like, which comprises a'.g;ldinf.,fv to the water-a 'small quantity of the substance. of a water-,solublewater-treating glass,lsaid glass consisting ofr a homogeneousiusonproduct analytically conl r.sisting `of A20, P205 and MO wherein A isv alkali metal and M is divalent metal selected from the group consisting of magnesium, calcium, strontium and barium, the P205 being present in the range from 331/3 to 50molar per cent of the total ymolar content of said oxides, and the M0 being `present Vto an extent'in the range from 2.5 to 30 molar rper cent of said total molar content ofsaid oxides, and the A20 being present in anamount lranging upwardly from a `minimum of .20 molar per cent of said total molar content.

12. The method of treating water which comprises adding theretoa water solution containing .dissolved water-soluble glass consisting of a homogeneous fusion product analytically consisting ofjA20, P205 and M0 wherein A is-alkali metal and M` is divalent metal selected from the group consisting of magnesium, calcium, strontium and barium, the P205 being present in therange from 331/3 to 50 molar -per `centof the total molar content of said oxides, and the M0 being present to an extent in the range from 2.5 to 30.molar per cent of said total molar content of said oxides, and the A20 being .present in an amount ranging upwardly from a minimum of 20 molar per cent of Said total 1110.121. .content 13. The method of treating water having hardness which comprises adding to the water the substance of a water-soluble water-treating glass,

said glass consisting of a homogeneous fusion product analytically consisting of Na20, P205 and M0 wherein M is divalent metal vselected from the group consisting of magnesium, calcium, strontium and barium, the P205 being present to 50 molar per cent of the total molar content of said oxides, and the M0 being'present to an extent inthe range from 2.5

to 17.5 molar per cent of the total molar content of said oxides, and the Na20 being present in an of magnesium, calcium, strontium and barium,

the P205 beingpresentin the range from 331/3 to 5,0 molar percent of the total molarcontent of said oxides,fand the M0 `being presentI to an extent in the range from 2.5 to 17.5 molar per cent of the total molar content of said oxides, and the Na20 being present in an. amount ranging upwardly from 32.5 molar per cent of said-` total molar content. i' f 16.V Alprocess'of softening water which comprises subjecting a quantity of waterto contact Withf a water-soluble glass consisting of a homogeneouslfusion product analytically consisting of -Na20, P205 and MO wherein Mis "divalent metal selected from the group consisting of magnesium, calcium', strontium and barium, the P205 being present in the rangejfrorn 331/3 to 50 molar per cent of the total molar content of said oxides, and the M0 being present to an extent in the range from'2-5 to 17.5 molar per centof the total molar content of saidoxides, and the Na20 being present in an amount ranging upwardly from' 32.5 molar per cent of said total molarcontent.

yx17. A Aprooessfor inhibiting in hard waters the precipitation of compounds having the hardening'elements of the water, which comprises adding rto the water the substance of a water-soluble water-treating glass, said glass consisting of a homogeneous fusion product analytically consisting of NazO, P205 and M0 wherein M is divalent metal selected yfrom the group consisting of magnesium, calcium, strontium and barium, the P205 being present inthe range from 331/; to. 50molar per cent ofthe total molar content of. said oxides, andthe MO-being present to an extent in the range from 2.5 to 17.5 molar per cent of the total molar content of said oxides, and the Na20 being .present in anamount ranging upwardly from 32.5 molar per 'cent of said total molar content.

18. Themethod of treating boiler water to inhibit the formation of scale which comprises adding to the Water the substance of a Water-soluble water-treating glass, said glass consisting of a homogeneous fusion productanalytically consisting of Na20, P205 andMO wherein M is divalent metal selected from the group consisting of mag.-`

range from 2.5 to 17.5 molar per cent of the total molar molar content of said oxides, and the Na20 being present in an amount ranging upwardly from 32.5 molar per cent of said total molar content.

19. The method of treating domestic washing waters for bathing, laundering, dish-Washing and the like, which comprises adding to the water the substance of a water-soluble lwater-treating glass, said glass consisting of a homogeneous fusion product analytically consisting of Na20, P205 and M wherein M is divalentmetal selected from the group consisting of magnesium, calcium, strontium and barium, the P2O5being present in the range from 33 V3 to 50 molar per cent of the total molar content of said oxides, and the M0 being present to an extent in the range from 2.5 to 17.5 molar per cent of the total molar content of said oxides, and the Na being present in an amount ranging upwardly from 32.5 molar per cent of said total molar content.

20. The method of treating water which com-- prises adding thereto a water solution containing dissolved water-soluble glass consisting of a homogeneous fusion product. analytically consisting oi Na20, P205 and M0 wherein M is divalent metal selected from the group consisting of magnesium, calcium, strontium and barium, the P205 beiner present in the range from 331/3 to 50 molar per `cent of the total molar content of said oxides, and the M0 being present to an extent in the range from 2.5 tov 17 .5 molar percent of the total molar content of said oxides, and the N azO being present in an amount ranging upwardly from 32.5 molar per cent of said total molar content.-

21. The method of treating water having hardness which comprises adding to the water the substance of a water-soluble water-treatingglass, said glass consisting of a homogeneous fusion product analytically consisting of A20, P205 and M0 wherein A` is alkali metal and M is divalent metal selected from the group consisting of mag` nesium, calcium, strontium and barium, and said glass having a composition lying in a predetermined area oi a trilinear diagram of molar content of said oxides, the said area being bounded by the, lines as follows: the line of 2.5 molar per cent M0; the line of 50 molar per cent P205; the line of 20 molar per cent of A20; and the line of 33 1/3 molar percent of P205.

22. The method. of treating water having hardness which comprises. adding to the water the substance of a' water-soluble water-treating glass,

said glass consisting of a, homogeneous fusion.

produc-t analytically consisting of A20, P205 and M0 wherein A isA alkali metal and M is divalent metal selected from the groupv consisting of magnesium, calcium, strontium andA barium, and said glass having a composition lying. in a. predeten minedv area of a trilinear diagram of molar content of said, oxides, the said area lying on a band across the diagram which band is bounded by lines parallel to one side of the diagram and' corresponding respectively to 33% and 5.0 molar per cent or P205, said area being boundedparallel to la second side of the diagram by the line corre,-

sponding 'to 2.5 -molar per cent of MO, and being bounded parallel to the third side of the diagram by the line of aboutv .20 molar per cent of A20, which latter line kintersects the line of 50 molar per cent of P205at about molarper cent of M0.

23. The method of treating Water having hard .ness which comprises adding to the water the substance of a water-soluble water-treating glass, said glass consisting of a homogeneous fusion oduct analytically consisting of Na20, P205 and gO, the yP205 being present in the range from 33 1/2 to 50 molar percent of the total molar content of said oxides, the MgO being present to an extent in the range from 2.5 to 30 molar per cent of said total molar content, and the Na20 being present in quantity ranging upwardly from 20 molar per cent of said total molar content.

24. The method of treating water having hard ness which comprises adding to the water the substance of a `water-soluble water-treating glass, said glass consisting of a homogeneous fusion product analytically consisting of NazO, P205 and MgO,` said glass having a composition defined by the area of a trilinear diagram of molar content Aof said oxides, which areais bounded by the lines as follows: the line of 2.5 molar per cent of MgO; the line of molar per cent of P205; the line of `20 molar per cent of Na20; and the line of 331/3 molar per cent of P205.

25. The method of treating water having hardness which comprises adding tothe water the substance of a Water-soluble water-treating glass, said glass consisting of a homogeneous Afusion ,i product analytically consisting of Na20, P205 and MgO, said glass having a composition defined by the area of a trilinear diagram of molar content of said oxides, which area lies ony a band across said diagram, which band is bounded by lines parallel to one side of the diagram and corre'- sponding respectively Ito 331/3 and 50 molar per cent of P205, said area being bounded parallel to a. second side of the diagram by the line corresponding to 2.5 'molar per cent of MgO, and being bounded parallel-to theY third side of the diagram by the line of about 20 molar per cent of Na20, which latter line intersects the line of 50 molar per cent of P205 Aat about 30 molar per cent v of MgO.

26. The method of treating Water having hardness which comprises adding to the water the substance of a water-soluble water-treating glass, said glass consisting of a homogeneous fusion product analytically consisting of Na20, P205 and MgO, the P205 being present to the extent of substantially 50v molar per cent of the total molar content of said oxides, the MgO being present to an extent in the range from 2.5 to about 30 molar per cent of said total molar content, and the N aaO being present to an extent ranging upwardly from about 20 molar per cent of said total molar content.

`errantes s. KING. 

